In general, a refrigerant system performs a refrigerant cycle including compressing-condensing-expanding-evaporating to heat and cool interior.
The refrigerant system includes an indoor unit performing heat exchange between refrigerant and indoor air, and an outdoor unit performing heat exchange between refrigerant and outdoor air. The indoor unit includes an indoor heat exchanger performing heat exchange between the refrigerant and the indoor air, a fan ventilating the indoor air, and a motor rotating the fan. The outdoor unit includes an outdoor heat exchanger performing heat exchange between the refrigerant and the outdoor air, a fan ventilating the outdoor air, a motor rotating the fan, a compressor compressing the refrigerant, an expansion portion expanding the refrigerant, and a 4-way valve changing flowing direction of the refrigerant.
Further, when performing indoor cooling, the indoor heat exchanger becomes a evaporator and the outdoor heat exchanger becomes a condenser. When performing indoor heating, the indoor heat exchanger becomes a condenser and the outdoor heat exchanger becomes an evaporator. Switching of the cooling and heating is performed by changing flowing direction of the refrigerant by the 4-way valve.